The present invention relates to a device for adjusting the pressure between a floor cleaning implement of a floor cleaning machine and a floor. The floor cleaning machine can be one of many types of floor cleaning and treating machines, such as scrubbers, sweepers, and the like. These types of machines can be used for the cleaning of hard surfaces of large floor areas in hotels, factories, office buildings, shopping centers and the like.
In general such machines comprise a movable body supported by a pair of drive wheels and one or more caster wheels. With a scrubber, the body carries a scrubbing device, reservoirs for storing fresh and spent cleaning liquid, a device for dosing fresh cleaning liquid onto the floor, and a squeegee/vacuum pickup system for recovering spent cleaning liquid from the floor.
The scrubbing device normally comprises one or more brushes or scrubbing pads, a motor for driving the brushes, and a device for lifting the brushes off the floor when large areas are traversed without any cleaning action being required.
A typical conventional floor cleaning machine has the problem in that a force for pressing the pad against the floor-surface is changed during operation, due to various causes such as wear of the pad, reduced voltage of the batteries, state of the floor-surface, and the like, and as a result, the quality level of the polishing job for the floor-surface is changed. If the pad pressure is too strong, there is a possibility that the wax applied to the floor-surface comes off and the floor-surface may be scratched. In contrast, if the pad pressure is too weak, a sufficient polishing effect can not be obtained.
Conventional devices regulate brush/pad pressure many different ways. For example, some devices monitor the current within the scrubbing motors to determine the brush pressure and adjust the brush pressure actuating the lifting device for the scrubbing assembly.
The present invention has been designed to overcome some of the complications and/or problems inherent in the conventional devices.